how can I fix the P0301 code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Spark Plug

1. Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
2. Remove the spark plug using a socket wrench.
3. Inspect the spark plug for wear; if it's fouled or worn, replace it with a new spark plug.
   • Torque the new spark plug to 13 ft-lbs (17 Nm).
4. Reinstall the ignition coil, ensuring the connector is securely attached.

3. Check and Replace Ignition Coil (if necessary)

1. If the ignition coil showed signs of damage, remove it from the engine.
2. Install the new ignition coil in place of the old one.
3. Reconnect the electrical connector and ensure it clicks into place.

4. Inspect Fuel Injector

1. Remove the engine cover if necessary to access the fuel rail.
2. Disconnect the fuel injector connector for cylinder 1.
3. Use a multimeter to test the injector for resistance; if it’s out of specification, replace the injector.
4. Reinstall the connector after ensuring proper operation.

5. Perform Compression Test (if misfire persists)

1. Remove the spark plug from cylinder 1.
2. Insert the compression tester into the spark plug hole.
3. Crank the engine and observe the compression reading; it should be within manufacturer specifications (typically around 180 psi).
4. If compression is low, further investigate for possible head gasket failure or valve issues.